Green tea (Camellia sinensis) for patients with knee osteoarthritis: A randomized open-label active-controlled clinical trial

Hashempur MH, Sadrneshin S, Mosavat SH, Ashraf A · Clinical Nutrition

The only randomized human trial of a green tea preparation against a joint endpoint. Mean change favoured the green tea arm for VAS pain (p = 0.038), total WOMAC (p = 0.006) and WOMAC physical function (p = 0.004). The WOMAC pain and stiffness sub-scores did not differ (p = 0.163 and p = 0.150) — so the two pain instruments in the same trial disagreed. One adverse event, gastric upset, in the control arm.

Population

Adults with knee osteoarthritis, Shiraz, Iran

Intervention

Green tea extract tablets plus diclofenac for 4 weeks

Comparator

Diclofenac alone

Limitations

Open-label with no placebo: the control group knowingly took one tablet while the intervention group took two, against a self-reported pain endpoint. Four weeks, n=50, single centre, extract tablets rather than brewed tea, and given on top of an NSAID so it tests adjunctive use only. That VAS pain improved while WOMAC pain did not is the kind of split an unblinded design produces.